By The Wayside
by bravevulnerability
Summary: "This is our life, not just mine anymore, and I'm happy about that," she promises him, smoothing over old wounds and doubts with soft words, nipping on his bottom lip when he leans in to kiss her again. "Besides, you on the bike is extremely hot." Castle and Beckett take that cross-country trip. Post-ep for 8x18, 'Backstabber'.
**A/N: Thank you so much to Alex for reading this one over and providing such smile inducing encouragement.**

* * *

 _"Some of the things you love have fallen by the wayside... I think you should take the bike on a cross-country trip. It's something you've always wanted to do."_

 _"This is amazing, I love this, but I don't want to do this alone."_

* * *

The tremble of the motor between her thighs, the wind slapping the exposed skin of her cheeks, tangling through the strands of hair slipping free from her helmet, is exhilarating. It's only their first day of travel in this cross-country expedition they've spent the last two weeks planning, mapping out their routes until the geography was imprinted on both of their brains. They have a schedule (the goal is to make it to Syracuse today, Rochester if they're both up to it), but she's in no rush. The most gratifying part of this adventure will be the experience, the journey across the United States with her husband eating up the miles alongside her.

Castle signals from behind her as they approach a gas station and Beckett nods her understanding, easing her grip on the clutch and turning into the parking lot with Rick close behind. They've only been riding for two hours, the air still crisp and biting with midmorning chill, but Castle has managed to thoroughly impress her within that short time.

It's not that she had doubted him, she'd actually had no idea what to expect of him as a rider, but from the second they pulled out onto the streets earlier, he had shown expert skill, weaving through traffic and maintaining control of the bike without hesitation or fumble.

They park their bikes near twin gas pumps, Castle cutting his engine first, removing the helmet from his head and dismounting from the bike.

She had once told him that she doubted he could handle the sight of her straddling a bike in tight, black leather, but she had quickly learned that it was the other way around. They had hours before they stopped for the day, but she couldn't wait to check into a hotel with him, strip the fitted clothing from his skin.

"How are you feeling?" Castle asks once she's cut her own engine, nudged the kickstand into place.

The station isn't crowded, a few semi-trucks and 18-wheelers parked off to the side, tourists crowding the attached convenience store, so she doesn't stop him when he abandons his bike to approach her, grinning as she tears the helmet from her head. Her hands rise to cup his face the moment he's close enough, hauling him in forward just as she rises to meet his mouth with the firm press of hers.

Castle chuckles against the seal of her lips, the outpouring of her jubilation, his arms banding around her shoulders and his fingers snaking through her knotted hair to cup her skull.

"I'm going to take that as a 'good'," he mumbles, dragging his hands down her sides to splay his fingers atop the leather encasing her frame.

"It's amazing, Castle," she hums, brushing one of her hands through his hair, ruffling the locks that had been pressed down by the helmet. "Just you, me, the open road and the world flying by."

His eyes are alive with it too, rippling a sharp, striking blue like the clear skies overhead, reflecting her excitement back at her while he drifts forward again, smears his lips to her forehead.

"Thank you so much for wanting me to come with you," he murmurs, his gratitude staining her skin, and Kate draws back enough to see his face, to offer him a smile as her thumbs graze his ears.

"You know I still appreciate my solitude, but nearly a month driving across the country? I would never want to do that without you, Rick. This is _our_ life, not just mine anymore, and I'm happy about that," she promises him, smoothing over old wounds and doubts with soft words, nipping on his bottom lip when he leans in to kiss her again. "Besides, you on the bike is extremely hot."

Castle growls, causes her bike to wobble and her body to rumble with laughter as he presses in closer, his lips quivering with a grin against hers. "You have no idea how much I love my view, Beckett."

"Go fill up and then we'll grab a snack," she mumbles, smudging one last touch of her mouth to his jaw before nudging him away.

"As soon as we decide where to stay for the night-"

"Yeah, I know," she smirks, narrowing her gaze on him as he walks around the pump to return to his bike and prepares to fill his tank with gasoline, bumping into a small pillar along the way.

* * *

"Everything hurts."

The bed shifts as Kate crawls atop the mattress, climbs over him with a sigh, and eases her body to fit against his, the warm weight of his wife soothing his aching muscles, the throbbing beat of soreness.

"Told you we should have stopped in Syracuse instead," she murmurs, pressing her elbow into the pillow beside his head, tilting her cheek into the support of her hand. She had awakened before him and her hair is still wet from her shower, excess water trickling down her forearm, staining the white cover of the pillow. "Too many hours on the road for the first day."

He groans in agreement and closes his eyes against the morning light streaming through the hotel window, the knowing glimmer in Kate's eyes. They had arrived in Rochester late yesterday afternoon, had a nice dinner and checked into a hotel not far off the highway, and he had felt fine, _better_ than fine.

A day of travel with Kate, bare exposure to the sun, the earth and the air whipping around them for miles, had been incredible. He had loved every second of it, and had felt how much his wife enjoyed it the second the door to their room slammed shut with him against it.

But he's really not loving it now.

"Why am I alone in my agony?" he whines, listening to Kate huff in amusement above him.

"I'm sore too, but I've ridden for long periods of time before, babe. You haven't. This is new for your body," she reasons, stroking her fingers through his hair and dispelling the pout of his lips with the tap of her thumb. "There's no rush, you know. If you're feeling this bad, we can camp out here for a day."

Castle's eyes flutter open to study her, but her gaze is gentle, a calm sea of hazel staring back at him. She had taken an entire month off of work for this, something he is still shocked she was able to manage, and with the arrival of this vacation had gone her sense of urgency, her usual need for routines and planning. Aside from their route across the country, she had been surprisingly laid back about the entire process of preparation for their trip.

"You're sure? I could still ride, Beckett, just a little stiff," he promises her, flexing the muscles of his thighs, attempting to maintain a straight face through the ripple of tenderness through his veins, but Kate shakes her head.

"Pittsburgh can wait an extra day."

"What will we do in the meantime?" he asks, quirking his brow at her, the pleasant spill of arousal steadily melting away the ache of his limbs as he watches her eyes darken, rivers of gold circling the widening pools of her pupils.

Kate coils her leg around his as she rises up on her knees, straddles his hips like she straddles her Harley, and splays her hands over his naked chest.

"Make Rochester an even more memorable stop on this trip."

* * *

Halfway through their journey from Chicago to St. Louis, Castle has his first close call, the closest thing to an accident they've encountered since their journey began.

It's raining, hard, and she's about to suggest they find somewhere to pull over, wait out the increasing storm for a couple of hours, when the sedan in front of Castle squeals to a stop. Beckett is riding behind him for a change, a way to alter their daily routine on the road, and she has more than enough time to slow on the slick strip of highway, but Rick doesn't.

Her heart seizes in her chest as she watches his shoulders tense, his entire body fighting to control the bike, but he's moving too fast to stop, the sheets of rain worsening his attempts to avoid the sudden stop of the car on the otherwise barren roadway.

He just narrowly manages to avoid slamming into the trunk of the vehicle.

Kate's hand shoots up once he's passed the car, signaling for him to pull over on the side of the road and he doesn't attempt to argue.

"Castle," she breathes once her bike is parked safely beside his, ripping the helmet from her head and blinking through the spill of rain down her face.

He's shaking when she reaches him, the bike off, but his body trembling, and Kate helps him ease the helmet from his skull.

"Are you okay?" she questions, her fingers scrambling to his neck, desperate to feel the beat of his pulse regardless, to caress his skin with the drops of rain. "Castle?"

"I'm okay," he promises, blinking a couple of times before he can really look at her, prying his fingers from the handlebars and tugging off his gloves to wipe at the water streaming into his unguarded eyes. "I'd be better if people knew how to drive."

Kate tosses a scowl at the gold sedan now moving on ahead of them, contemplates memorizing the license plate number, but returns her attention to Castle instead. "I'm so sorry, Castle. I should have checked the weather app before we-"

"Hey, no, it's not your fault," he placates her without missing a beat, raising his voice to be heard over the rain, but Kate shakes her head, bands her arm around his neck and feels the pulse of adrenaline hammering through his frame.

The highway they're parked on isn't busy, a few lone cars speeding by endless fields of corn, mist from the puddles forming along the streets spraying their shins with each passing vehicle, but the rainstorm is beginning to calm in its intensity and so does the pound of Castle's heart.

"We should stop for a while, get something to eat and dry off-"

"We're more than halfway to St. Louis," Castle states, squeezing her hips and pulling back enough to offer her a reassuring spread of his lips, but it does little to quiet the uproar of anxiety rioting through her bloodstream. "The weather is getting better. We can finish our plan for today."

He's right, the downpour has lessened to a light shower now, but the idea of driving any farther after watching him barely escape a collision has her heart rabbiting painfully in her chest. Part of her wants to walk the bikes to the nearest town, find a way to have them shipped back to New York and take a plane back home with Castle safely strapped in beside her-

"Kate." Her eyes flicker up to meet his, the understanding in his gaze shining bright blue amidst the grey of the world around them.

"I just never thought about getting into an accident," she confesses, chewing on her bottom lip to stop herself from thinking too hard, from opening the internal Pandora's box of worst case scenarios she hadn't even touched throughout this trip. "I couldn't lose you like that, we've been through too much for me to-"

"Kate," he calls again, softer this time, skating one of his hands up her cheek to bury in the drenched tendrils of her hair. "Nearly crashing into that car was terrifying, but I'm okay. And I would have survived. We were in bad conditions with a bad driver on the road with us," he murmurs, his thumb sliding back and forth over her temple. "Otherwise, we've both been careful throughout this entire trip and haven't encountered any issues. We'll be even more careful now and we'll be fine."

The rain has stopped, the air around them quiet with nothing more than the drip of residual water through the leaves of corn in the nearby fields, and Kate sighs, trails her fingers along the path of water sluicing down the sleeve of his leather jacket.

"We've known each other for eight years, but I - after this past year, it feels like a new beginning for us," she whispers, training her gaze on the raindrop clinging to his jawline, stubbornly refusing to fall. "It feels like I just got you back and I can't stand to lose you again, Castle. I won't - I can't survive what it would do to me."

The hand in her hair eases down to curve at her nape, his palm a warm, reassuring anchor that draws her in closer.

"Beckett, I think if the universe had any intention of letting you get rid of me, we wouldn't be here right now." The laugh falls strangled from her lips, but she lifts her eyes to him with the beginnings of a smile tugging at the corners of her mouth. "You know as well as I do that there are no guarantees, but as long as I can help it, I'm not going anywhere."

All she has to do is tilt forward to taste the promise on his lips, seal it to hers and quell the waves of paranoia that crash through her stomach.

"And we've beaten the odds too many times to die on the side of the road by a lame cornfield," he scoffs, causing her lips tremble with laughter now, and Kate shakes her head.

"It'd be an insult," she agrees, dusting another kiss to the corner of his mouth, sipping the droplets of rain from his skin before leaning away to pluck her helmet from the back of his bike. "Okay, Castle. Let's finish the rest of the ride to St. Louis."

* * *

Riding through the Rocky Mountains nearly two weeks into their trip is unquestionably his favorite part so far. Despite the amount of travel he's done throughout his life due to his career, he never spent much time in Colorado, never had the chance to explore the Rockies, and it's… breathtaking.

He's distracted the entire time - the spring of magnificent trees reaching for the skies, the snow dusted mountains all around them, the thrill of climbing higher, following the curve of the mountain towards the sky providing a slew of riveting sights and sensations. The advantage from up above, seeing the beauty their planet has to offer splayed out beneath them, had him battling with his concentration more often than not.

Kate finally signals for him to pull over just after they pass one of the lakes, the water sparkling with reflections of the starlight overhead, and Castle inches the bike onto the patch of snow sprinkled grass that covers the shoulder of the road. He cuts the engine once he's parked neatly behind Kate's Harley, but dismounts when his wife eases from her bike to maneuver the Softail within a small cluster of pines and evergreens, a nice little tourist stop for scenic photos.

"What are we doing?" he asks as Kate shakes her hair free from her helmet, props the safety-wear atop the GPS between the bike's handlebars.

The sun has set and all that's left amidst the sky are strips of fading color, a streak of purple, a layer of blue, and the shade of midnight darkness descending illuminated by a plethora of stars. They don't usually ride this late into the evenings, always preferring to be settled in for the night before darkness falls, but they had already been so close to the Rocky Mountains National Park and riding the route of Highway 34 during the sunset had been an opportunity they mutually hadn't wanted to pass up.

"Just enjoying the scenery, Castle," she grins, tilting her face to the night sky while he sits on his bike, watching her. The beginnings of moonlight dapple along her skin, kiss the arch of her throat, and for the hundredth time since they set out on this trip, gratitude flushes his system.

When he had restored her bike, he had crossed his fingers that she would ask him along on the cross-country trip he'd planned to suggest, but he hadn't been positive that she would extend the invitation. A small, still wounded part of him had secretly feared that she would rejoice at the time away, crave the space to clear her head, but she hadn't even considered the idea. And this trip with her… it's been better than he could have imagined.

They've had their fights, petty arguments born from spending so much consistent time together, but if anything, he feels closer to her, their connection solidified. This past year has brought many uncertainties their way and he's worried more than once that he would lose her, either by her own choice or at the hands of a more powerful force, but right now, he feels invincible with his wife by his side, more secure in their marriage.

They feel unbreakable again.

"We're in the Rocky Mountains, there's practically no one on the road right now, it's dark…"

Her eyes slide to snag his, mischief alight in her gaze and flirting with the corner of her mouth.

"Katherine Beckett, are you thinking about marking something off of your kinky bucket list right now?" he gasps and she stifles a laugh, but steps away from her bike, sways her hips as she crosses the short distance to his.

"Stop calling it a kinky bucket list," she mutters, bracing her palms at his shoulders, but he's already scooting backwards, making room for her to sit in front of him and checking the kickstand to ensure the bike will remain balanced.

"What would you call a secret list of _intimate_ scenarios that you intent to act on before you die?" he muses, steadying her with his hands to the bones of her hips as she swings one of her legs over the bike.

Castle glances over his shoulder to the road, but no, she stopped them with intent, picking a perfect spot that would seclude them from the highway. No one would notice them through the thin shade of the tree branches and shrubbery. Meanwhile, he had the glorious view of his wife in lap and the dreamlike setting of the mountains bathed in stardust behind her.

Kate settles in front of him, hooking her legs around his waist and her arms around his neck, quite proud of herself if the smile stretching across her lips is any indication.

"I call it living adventurously."

Castle slips his hands beneath the leather of her jacket, the layers of her shirt and the thermal underneath, splaying his palms over the lattice of her ribs, the warm skin of her sides.

"You definitely make life an adventure," he chuckles, skimming the waistband of her jeans, listening to her breath catch at the sweep of his thumb to the sensitive flesh beneath her navel.

Kate's arms tighten around his neck as her body hums with anticipation beneath his hands, gentle fingers tunneling through his hair and scratching at his scalp as Castle trails his lower, his thumb circling the button of her pants.

"Never boring," she reminds him, her smile bumping his, the breath of her laughter coating his lips before she captures his mouth, leaves him just as breathless as the view.

* * *

"The bikes made it back to the garage safely," Castle announces as she emerges from the hotel bathroom, her hair falling in soft curls around her bare shoulders, the dress she had purchased earlier catching her husband's attention the moment he glances up from the phone in his hand. "Wow."

After three weeks on the road and over four thousand miles of maneuvering their motorcycles across the country, they had made it to their destination of San Francisco yesterday morning. Deciding to stay along the California coast for a few extra days had been Castle's idea, one she had happily agreed to, and now, for the first time since their journey began, they're going out on a date that won't be taking place in a Midwestern diner or a great city's tourist attraction. For the first time in three weeks, she had a chance to indulge her feminine side and dress up for him, and his reaction has her feeling all the more pleased with her efforts.

"That's good news," she murmurs, smoothing her hands down the flowing purple fabric at her thighs.

Their mode of transportation had forced them both to pack light throughout their expedition, only one extra change of clothes tucked away into their travel bags and most necessities bought along the way to avoid being weighed down, but today they'd been able to go shopping together. And while Castle had purchased new jeans and a crisp button down, she had found a sundress that managed an appealing balance of tasteful and tantalizing.

"You're stunning," he states, the information on their bikes' lone journey back to New York forgotten as he rises from the edge of the suite's king-sized bed, crossing the feet of space between them.

"You're not so bad yourself, Castle," she hums, affection swirling through her chest when his hands flutter at her waist, his eyes still caressing the swish of fabric above her knees, the hint of cleavage the neck of the dress allows, like he's still as genuinely mystified by her as he was eight years ago. "Hey."

His eyes snap up to meet hers and Kate chuckles, lifts her fingertips to the clean-shaven line of his jaw, still mourning the beginnings of his beard, and grazes her fingertips along the warmth of his skin.

"I love you."

The striking shade of his irises softens into the beautiful cerulean she fell in love with so long ago, adoration still illuminating his gaze as the lopsided smile claims his lips.

"I love you too." Rick's hand catches hers at his jaw, his thumb stroking the wedding band on her fourth finger, and his lips stretch wider. "Always."

His free hand covers her waist when she arches on the toes of her ballet flats, yearning to be as close as possible when she kisses him, painting an unspoken promise with her tongue that he determines all too well.

She was excited to return home at the end of the week, reintegrate back into their beloved city, but savoring the last of her adventure with Castle almost has her wishing that they could live in this moment, this state of being, forever. Never go back.

"We could do it, you know," she breathes, her fingers climbing the back of his neck to tangle in the fine hairs at the base of his skull. "Spend the rest of our lives traveling the world."

Castle lowers his forehead to rest against hers, the smile still in place and his hand offering her hipbone a reassuring squeeze.

"If I thought it would make you happy, Kate, I'd let you lead me across the universe," he murmurs and she knows that without a doubt that he means it, that he would give her the world if she asked for it. "And if it's what you want, all you have to do is say the word."

She sighs, bumps the tip of her nose into his and opens her eyes to let their lashes tangle. "Does that offer expire?"

Castle huffs, his fingers slipping from hers to circle her wrist and brush across the beat of her pulse. "I don't care where we end up, what the next chapter holds for us, as long as I'm with you. That's my priority, Beckett." Her heart exalts with the words, information she's always known, put faith in, but a welcome comfort to hear nonetheless. "No expiration date on that."


End file.
